Simulate an FMU

The otfmi simulate function instanciates, initializes and simulates the FMU.

First, retrieve and load the FMU deviation.fmu.

import openturns as ot
import otfmi.example.utility
import matplotlib.pyplot as plt

path_fmu = otfmi.example.utility.get_path_fmu("deviation")
model = otfmi.fmi.load_fmu(path_fmu)

Note

model is a PyFMI object, loaded with otfmi’s overlay.

As such, model.simulate() is a pure PyFMI method.

Use otfmi.fmi.simulate(model) to benefit from otfmi’s overlay.

otfmi simulate function notably eases initializing a FMU, see Initialize an FMU with non-default values.

On top of the initialization keywords, PyFMI simulation keywords can be employed:

result = otfmi.fmi.simulate(
    model,
    start_time=0,  # PyFMI keyword
    final_time=1,  # PyFMI keyword
    initialization_parameters=(["L"], [300]),
)  # otfmi keyword
print("y = %g" % result.final("y"))

Simulation interval    : 0 - 1.0 seconds.
Elapsed simulation time: 0.01338147100000242 seconds.
y = 22.5

We can use these keyword to plot the deviation Y as function of the beam length L:

inputSample = ot.RegularGrid(1.0, 10.0, 10).getValues()

list_output = []
for length in inputSample:
    result = otfmi.fmi.simulate(model, initialization_parameters=(["L"], [length]))
    list_output.append(result.final("y"))
outputSample = ot.Sample([[xx] for xx in list_output])

plt.figure()
plt.plot(inputSample, outputSample)
plt.show()

Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01315840800003798 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013027735000036955 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013162565000016002 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013194364000014502 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013130885999999009 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013104617000010421 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013146474999985003 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013063341000020046 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013101482000024589 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01309302600003548 seconds.

The interest of the higher-level functions are:

- avoid the for loop on the points of the design of experiment,

- automatic formatting of the simulation outputs.